1. Field of the Invention
This invention relates to a compound of which molecular structure and solubility in a solvent can be changed by retro-Diels-Alder reaction and a method for producing the same. The present invention also relates to an ink for use in recording such as ink-jet recording, an ink cartridge, a recording unit, an ink-jet recording apparatus, a recording method and a recording medium. The present invention also relates to a pattern-forming method for use in, for example, production of a DNA chip and a liquid composition used in the method. The present invention also relates to a method for detecting environmental history to detect whether or not an object has undergone heating etc., and an article of which environmental history is detectable.
2. Related Background Art
A technique for controlling the solubility of a compound in a solvent according to the conditions has been strongly desired in various technical fields.
For example, in the field of ink-jet recording, it is preferable, in view of the ink stability, that the coloring material in ink is in a dissolved state, i.e., in a monomolecular state. On the other hand, in view of high quality image formation, when such an ink is provided on a recording medium, it is preferable that the coloring material in the ink is quickly separated from the solvent so that it can be retained on the surface of the recording medium or in the vicinity thereof. So-called dye ink can satisfy the former requirement, and so-called pigment ink the latter, but it is difficult to satisfy them both at the same time. In recent years, various techniques have been proposed for imparting characteristics of dyes to pigments by, for example, refining pigments or introducing water-dispersible functional groups onto the surface of pigments, but there is still great room for improvement. Meanwhile, with the drastic improvement in performance of ink-jet printers, it has been proposed to use an ink-jet printer as an apparatus for producing devices having fine patterns, such as DNA chips.